/ Dictionary / Index B butabarbital sodium: Meaning and Definition of Find definitions for: bu•ta•bar'bi•tal so'dium Pronunciation: (by"tu-bär'bi-tôl", -tal"), [key] — Pharm. Pharm. a barbiturate, CHNNaO, used as a sedative and hypnotic. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. but butadiene Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language